Automatic calling device



J. G. BLESSING AUTOMATIC CALLING DEVICE Oct. 13","19'2'5- 1,556,905

Filed oct'. 18, 1921 2 Shuts-Shut 1 Imreu mr- H957 SELECTO J. G. BLESSING AUTOMATIC CALLING DEVICE Filed Oct. 18, 1921 2 Sheets-Sheet 2 ssco/m 551567098 CON/V12- C 7096 hmuwmw- JIIIIIIIIIHIHI JIIIIIIIIIIIIIIIIII Enid --Imren m Jul-m 1151555111 5%. Z.

Patented Oct. 13, 1925.

um'r so STATES:-

PATENT oer-ice JOHN G. BIJESSING, O]? CHICAGO; ILLINOIS, ASSIG-NORITO AUTOMATIGMELEGTRIC COMPANYQOF CHICAGO, ILLINOIS, A CORPO'RATION OFILLINUIS.

AUTOMATIC, CALLING DEVICE.

Application filed. October. 18, 1921. Serial No. .508.,4,78,f Y

T 0 all. whom it may concern Be it knownthat 1', JOHN BLESSTNG,

a citizen of the United States of'America, and a resident of Chicago, Cook Gounty,.and]

. State of. Illinois,have invented certain new and useful; Improvements, in. Automatic Calling Devices, ofwhioh thefollowingis aspecification. i

My invention relatesingeneral to animproved calling device andmore specifically.

to an. improved type of impulse. sending.

mechanism. for. use in transmittingcalling impulses to control the operationof: an. auto. matic switch of. any well knowntwo: wire type.

provide a. simple device for prolongingthe interval of time between the transmissionof the finalimpulseof one digit and the transmissionof the first. impulse of the. succeeding digit. It is well known that. sucha, calling device is used in practice to first send. one series of impulses tocause the vertical:mo,-. tion-of. the standardxtwo wire Strowger. selector, and the switch then operatesautos matically to select an idle trunk in. the groupelected, therefore sufficient time must be givento permit this automatictrunk selecting function before the; next series of' *impulses are transmitted. In order to accomplish the above resultI have constructed; *the device so, that the cam: is rotated an. additional. revolution each time the calling It will be.v understood.

device is operated; 2 that were no special means provided. tov prevent it, this dial when operated would move the camasufficient distance-to send anextra impulse. Means are provided as will be explained, for preventing the transmission of this extra impulse by. moving the oamout of. the path of the impulse springs at. arcriti cal time.

Other features of, my invention are the. provisionof a device which, is very simple in construction and'which requiresa mini-- mum. number of moving parts. Otherfeaw tures of improvement will be explained in the following detaileddescription oftlie ac companying drawings in which:

' Fig. .1' shows affront view of my improvedi calling device. in normal. position, with a portion of. the finger hold dialQ and a portion. oft-he number-dial. 3 broken. away, to more clearly show certain of the operating elements.

Among the features ofmy inventioni'isto Fig. 2'shows a normal position.

Fig.3 shows a front view of the device operated position, with the finger hold dial and'the number dialremovedl V L Fig. 4 shows a side vie-woffthe device with the finger stop5in its; normal position.

Fig. 5 shows aside view: of the device zvlththe. finger stop 5 in its operated posilOIl.

L Fig. 6 shows a sideview of'the finge hold. dial 2 andfthe eombinedgear and. spring cup. M I

Fig. 7 shows a complete front view off'the. dial, illustrating the order" in which the figures and letters are arranged. I s

Fig. 8 shows a schematic diagram of a trunking system to -which a calling device. of the type illustrated may be applied.

I have chosen to illustrat my invention in theform of a calling device suitable for. use, in what is commonlyltnown. as a-large capacity sy'stem,. it}, should be understood however. that my invention may be applied. equally well in any two wire system, the number of impulses being an immaterial' factor which maybe varied to suit require ments,

I will now describe the; various parts of the calling, device more indetail, and ex plain the operation, of the same,. reference being made to the various figuresof drawmgs.

Referring to Figure 1,.iny improved calls rear view ofthe device inv ing device consists: ofamonnting. plate 1',f

the. front side being asa whole'fso shaped asv to form. a cup.- In thecenter is, a post 21' (Fig. on which area plurality. of shoulders. formingfthreek distinct; sections. The lowermost;se.otionl acts as a. bearing point forthe gear and spring cup-4. Onth'e second section is. provided .aylug 22,,wh'ich 00- operates with an, aperture. on the inner end; of; spring 11, the outer end of spring 11 being fastened to a lug 23 onfltheinner side. offthe cup l. {The uppermost section ofthe. post21 acts as'a bearing point for the finger hold dial. 2. fThe. finger stop. 5 is; .eldli'n place, by the. screw 12. which also. serves to hold the finger hold' dial72' and the. gear. and spring 011 34 in place: Asecond post 25. acts as. an, axis for. the plate. 9 and"- the unit comprising gear. and pinion 6 and. 7. The, gear 8' is mounted on the shaft 16-, which extends throughthe plate 9" and a;

sleeve 38 which is fixed to the plate 9. The shaft 16 also extends through an elongated hole 31 (Fig. 2) in the mounting plate 1, a-nd'carries the impulse cam 33 as shown in Figure 2. The spring 10 is fastened to the mounting plate 1 and extends over the plate 9 to cause the plate 9 to be retainedin its operated position as will belater explained. The plate 9 carries two pins29 and 30', which co-operate with the arm 34 of the finger stop 5 to throw the cam 33 in and out of range of the impulse springs 39 and shunt springs 41. Pin 14 attached to the finger stop 5, co-operates with the pin 15 onthe finger hold dial 2 to return the finger stop to normal position after the dial has been operated. Referring to Fig. 3, the bracket 26 carries the shaft 27, which acts as an axis for the unit comprisinggear and ratchet 13 and 28. The ratchet-28 extends through a hole in the mounting plate 1, and co-operates with the governor assembly 37, which is also mounted on haft 27, as shown in 2. The rear of themounting'plate 1 has a raised portion 20 which forms a cup for the governor 37 "The shunt and interrupter springs 41 and 39 are mounted on a block 40' and the whole is held to plate 1 bythe screws 41'. Screws 41' also serve to hold spring 10 in place as shown in Fig. 3. In Fig. 6 is shown the finger hold dial 2,and the gear spring cup 4. -The finger hold dial has a machined shoulder 23 and a key 43. The cup 4 has its inner surface machined so that the shoulder and the cup snugly fit together-forming a unit. A slot 24 in-the cup 4 meshes with the key 43 to prevent any possible rotary movement of thecup independent of the dial. k

- The operation of the device is as follows: The operator inserts her finger in the hole corresponding to the desired digit and rotates the finger-hold dial 2in a clockwise direction as far as'it will go, carrying withit.

the finger stopl5 which will then be in the position shown in Figs. 3 and 5. The finger stop 5 moving intothis position engages the pin 30 and-"therebycarri'es the'jplate 9'into its operated position'as shown in Figs. 3 and 5, in which position the plate 9 isheld by the spring 10 (Figs. 1 .and 3) hen the plate 9 was moved into its operatedposition itcarried with it the sleeve 38, the gear 8,

shaft 16 and th e cam 33. The'sleeve. 38 is,

brought into operative relation to an insulated portion 42 of the shunt springs 41 which are thereby operated, The cam 33 is now inthe position shown in 5, 'in readiness to operate the interrupter springs 39.1 It may be stated at thistime that the springll (Fig. 1) is partially wound up at all times, butv is preventedlfrom unwinding by the pins 14 and 15, and bythe stop 5 en.- gaging the extreme end of the slot. 35 (Fig. 4). When the operator moved the finger hold dial 2 in, a clockwise direction additional'power was stored in the spring 11 and the pin 15, was carried out of engagement of pin 14. Upon releasing, the finger hold dial starts, on its return movement under tension of spring 11 and through the medium of gear 4, pinion 25 and gear 8. the cam 33 is caused to rotate. As soon as the cam has operated the interrupter springs 39 the number of times corresponding to the particular digit dialed, pin '15 on the dial 2 again engages the pin 14 of the stop 5,.and

before the cam 33 rotates sufficiently to again operate, the springs 39, the arm 34 of the finger'stop 5 engages pin 29 on plate 9 and carries the plate 9, gear. 8, shaft 11 and cam 33 to a point out of reach of the in-' terrupter springs 39 and therefore, the springs are not operated 'duringthe last revolutionof thecam. The instant the cam completes its last revolution the stop 5 comes into engagement with the end of the slot 35 (Fig. 4) and the dial andcam are brought to a positive stop. The pawl spring 39 co-operates with the teeth of ratchet wheel 28, so that when the gears revolve as thedial is moved in a clockwise direction, the spring may slide over the ratchet wheel. hen the gears operate in the reverse direction the governor is carried with them to regulate the return movement of the dial, but when the gears come to a positive stop the governor is permitted to rotate until it gradually comes to a stop, thus removing any undue strain on thegov ernor.

'Having chosen to illustrate my invention. as applied to a large capacity system, I have illustrated in Fig. 8 a trunking arrangement, which may be used in connection with a calling" device of the particular type disclosed.

Referring toFig. 8 I will now explain the trunking schemebriefiy. Three subscribers, telephone stations are indicated by the circles atthe upper left handcorner 'of the diagram. These stations are connected by the usual line circuits with the exchange, where they terminate preferably. in line switches of. some kind through the medium of which the lines when calling may be eX-' tended to idle first selector switches. The first selectors arethe first in the series of numerical switches which are used to establish connections inaccordance with called telephone numbers. The three squares labeled First selectors indicate three of these switches, and the inultiplebanks thereof, comprising2O levels of contact. sets are indicatedby the 20 heavy horizontal lines.' From each first selector leveltrunklines .extend'to a group. of. second selectors, there being in all 20 groups. of such secondselec tors. The group in which the'tru'nk-lines from'thefirst selector level terminate is'indicated in the drawing by three' -m'ore squares, labeled Second selectors, and the multiple banks are indicated by 20 horizontal lines as in the case of the first selectors. ilach group ofsecond selectors has access through its 20 bank levels to 20 groups of connectors. As in the case of the second selectors, only one group of connectors is shown, thisbeing the group accessible from the first level of the group of second'selectors shown. The connectors are likewise indicated by three squares, which are labeled Connectors inthe drawing, and the banks are indicated by the. heavy lines as before. It will be seen that the trunking scheme as a whole is similar to the usual one in common use, the only substantial difference being inthe capacity of the switches.

In, mechanical construction the selector and connector-switches maybe of -the ordinary vertical and rotary type, as shown in the U. S. patents to Keith, Erickson, and Erickson, Numbers 815,321 and 81'5,176,'the

shafts, however being provided with more notches to permit their wipers to be positioned on any one of the increased number of bankcontacts. The circuits may be of the well-known two-wire type, as illustrated by the U. S. patent to Newforth, No. 13,901, reissued April 13, 19 15.

The numbering of the bank levels will now be considered as shown in the drawing, the levels 1. to 0 correspond to the digits 1 role" on the upper half of the dial, while the levels 11 to 20 correspond to the digits in A, B, C, etc., as shown in the lower halfof'the dial. It should be understood that the invention is not limited tothe particular arrangement of letters and figures shown, as any desiredarrangement may be used. In the connectors, the individual contact sets in each level are similarly numbered, for they are selected by numerical operations under control of the calling devices.

Inasmuch as the connectors have 20 levels and 20 contact sets in each level, the capacity of each group of connectors will be 100 lines. There are 20 groups oficonnectors accessible to each group of second selectors, which would give each group of seconds'electors access to $000 lines; and since there are 20 groups of second selectors thetotal capacity of the 20 level system shown willbe 160,000 lines. hen this numberof lines is compared with the capacity of the ordinary four digit decimal system, which is 10,000 lines, the enormous increase in capacity may be realized.

It will be seenthat I have provided a very efficient and simply constructed type of calling device which prolongs the time interval between each series of impulses and which may be equally well applied to a percentage system as to a large capacity system. I do not wish therefore to limit my invention to the exact embodiment described, but desire to include and have protected by Letters Patent all embodiments thereof which come within the scope of the appendedcl'aims.

What I claim is:

1. In an impulse sending device, a spring for driving said device, a. rotatable finger hold dial having a keyed'shoulder thereon, a combined driving gear and spring cup for holding said spring, said cup somachined and keyed asto tightly fit over said shoulder making said finger hold dial and gear and spring cup as a unit.

2. In an impulse sending device, impulse springs, a. rotatable shaft carrying an impulse cam, for operating said springs, a gear on said shaft, a plate supporting said shaft and also carrying aplurality of pins, and a finger stop having an arm adapted to engage said pins to move said plate to permit said cam to operate said springs and for thereafter moving said plate to prevent further operation of said springs.

3. In an impulse sending device having two cycles of operation, a pair of impulse springs lying in planes parallel to each other, a cam foroperating said springs, said cam permanently fixed in a plane intermediate to said first planesfmeans for rotating said cam and means for causing said rotations to interrupt said springs during one cycle of operation and for causingsaid rotations to become ineffective during the other cycle of operation.

4. In an impulse sending device, a'rotatable finger hold dial, an impulse cam, interrupter springs operated by said cam, and means associated with said cam for removing said ca-m from operative relation to said springs by changing its axis to make further rotation of said caminefiective.

.5. In an impulse sending device, interrupter springs, a cam for operating said springs normally in inoperative relation thereto, a finger stop, and means associated therewith for moving said cam into operative relation to said springs.

.6. In a calling device, a finger hold dial, interrupter springs, a cam for operating said springs, a finger stop for limiting the forward and backward movement of said dial and for throwing said impulse cam into and out of operative relation to said springs, and means associated with said device'for holding said cam in operative relation to said springs until returned by said stop.

'7; In an impulse sending device, springs, aco'mbination comprising a gear, shaft, and cam, said cam normally in inoperative relation to said springs, a support for said combination and means for moving said support to place said cam in operative relation to said springs.

8. In an impulse sending device, interrupter springs, a cam for operating said springs normally in inoperative relation thereto, a finger stop, means associated therewith for moving said cam into operative relation to said springs, and a pair of shunt springs actuated by said means also.

9. In combination, interrupter springs, a rotatable cam for operating said springs normally in inoperative relation thereto, a movable finger stop, and means controlled by said stop for causing a lateral movement of said cam to bring the same into operative relation to said springs.

10. Ina calling device, a reciprocating dial, impulse springs, a cam for operating said springs, means for rotating said cam both on the forward and backward movements of the dial, and means for preventing the rotating cam from operating said sprlngs during the forward movement of the dial.

11. In a calling device, a reciprocating dial, a cam rotated by said dial during the setting movement thereof, a spring tensioned by said setting movement and effective to return the dial and rotate said cam during the return movement, impulse springs out of operative relation with said cam during the setting movement of the dial, and means for bringing the cam and springs into operative relation before the return movement of the dial begins.

12. In a calling device, a rotatablecam, means for revolving said cam a plurality of times in one direction and a like plurality of times in the opposite direction, impulse springs unaffected by'said cam during the first movement thereof, and means for causing said cam to operate said springs during its second movement. 1

13. In a calling device, a rotatable cam, means for revolving said cam a plurality of times in one direction and a like plurality of times in the opposite direction, impulse cam normally standing at a. distance from said springs, a support for the cam, means for moving said support to bring the cam and springs together, means for operating the cam to actuate said springs, and frictional means for retaining the support in position while the cam is being operated.

16. In a calling device, a reciprocating dial, aspring operating member, impulse springs normally out of the range of said member, a spring tensioned by said dial in the setting movement thereof for operating said member during the return movement, and means actuated at the end of the setting movement and before the return movement begins for bringing the springs and said member into'proximity with each other.

17; In a calling device, a cam, a gear and pinion for driving said cam, a shaft for the cam and pinion, a shaft for said gear, and a support for said first shaft pivoted on the shaft of said gear.

18. In a calling device of the movable cam type, a cam shaft; a gear and pinion for driving the cam shaft, a pivoted lever supporting the said shaft, and a common shaft for the gear and lever.

a 19. In an impulse transmitting device, impulse springs, means for operating said springs, said means normally in inoperative relation thereto, means for setting and then releasing the device-to transmit impulses, and means actuated at the end of the setting movement to bring the springs and spring operating means into operative relation.

20. In a calling device, a rotatable finger hole dial, impulse springs, a cam rotated by the dial for operating said springs, and means for moving the cam in a plane parallel to the dial for preventing certain of its rotations from operating the springs.

21. In a calling device, impulse springs, 'a reciprocating dial, a cam for operating said springs, said cam rotated by the dial both during the forward and backward movement of the dial, and means for preventing certain of the rotations of the cam from operating the springs both on the forward and backward movement of the dial.

In an impulse sending-device, a pair of impulse springs lying in planes parallel to each other, a cam for operating said springs,'said cam permanently fixed in a plane intermediate to said first planes, means for rotating said cam, and'means for moving the cam-to prevent certain of its rota tions from operating said springs.

In witness whereof, I hereunto subscribe my name this 14th day'of October, A. D. 1921. i 7

JOHN G. BLESSING. 

